templatetags: handle lazy values on unaccent filter (#58688)

tests/test_templates.py

@@ -217,6 +217,22 @@ def test_unaccent_templatetag():
     assert tmpl.render({'foo': 'FOO bar'}) == 'FOO bar'
     assert tmpl.render({'foo': 'félé'}) == 'fele'
 
+    # lazy mode
+    FormDef.wipe()
+    formdef = FormDef()
+    formdef.name = 'lazy'
+    formdef.fields = [fields.StringField(id='0', label='string', varname='foo')]
+    formdef.store()
+    formdata = formdef.data_class()()
+    formdata.data = {'0': 'félà'}
+    formdata.store()
+    context = CompatibilityNamesDict({'form': LazyFormData(formdata)})
+    tmpl = Template('{{ form_var_foo|unaccent }}')
+    assert tmpl.render(context) == 'fela'
+    formdata.data = {'0': None}
+    formdata.store()
+    assert tmpl.render(context) == ''
+
 
 def test_template_encoding():
     # django

wcs/qommon/templatetags/qommon.py

@@ -140,6 +140,7 @@ def urljoin(base, path=None):
 
 @register.filter
 def unaccent(value):
+    value = unlazy(value)
     if not value:
         return ''
     return force_text(unicodedata.normalize('NFKD', value).encode('ascii', 'ignore'))